Sintering machine



2 Sheets-Sheet l E.A W. SHALLOCK SINTE RING MACHINE March 28, 1933.

Filed March 21, 195o March 28, 1933. E. w, sHALLocK SINTERING MACHINE Filed March 21, 1930 2 Sheets-Sheet 2 Patented Mar. 28, 1933 UNITED STATES PATENT OFFICE EDWARD W. SHALLOCK, OF CHICAGO, ILLINOIS, ASSIGNOB TO AMERICAN BEC- LAMATION COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW YOBI SINTEBING MACHINE Application led Hai-ch 21, 1930. Serial No. 437,849.

This invention relates to the sintering of ores, flue dust, and other materials containing combustible ingredients, and has to do more particularly with a machine and method for sintering such materials.

Ores and other materials to be sintered are not uniform and frequently contain large proportions of relatively large particles, which may be considered as aggregates, as well as considerable proportions of relatively small particles, which may be considered as fines. In sintering materials which are composed either entirely or to a considerable extent of fines, when the sintering operation is conducted in machines known as the Dwight and Lloyd t pe, in which the material to be sintered is eposited ina layer upon .a perforated grate, the fine material has a tendency to stop up or clog, more or less, the perforations of the grate with the result that it 'is frequently quite dilicult to obtain the proper down-draft through the mass to assure proper sintering thereof during travel of the grate to the delivery or discharge end of the machine. Under such conditions, either the material is not properly sintered,

or the output of the machine is greatly cur-.

tailed due to the necessity of slowing down the speed of operation. The great majority, and in fact practically all, of the material treated in sintering machines contain an appreciable amount of relatively large particles or aggregates. It is the present practice, when sintering such materials in continuously operating machines, such as machines of the Dwight and Lloyd type, to deposit the material upon the moving grate with the coarse particles or aggregates and the relatively small particles or fines intermixed indiscriminately, with the result that a certain amount of stoppage of the perforations of the grate occurs with resultant slowing down in the sintering operation.

I have found that this objection can be avoided, and the output of a given machine greatly increased, by separating the fines and aggregates of the material to be sintered and forming upon the grate a lower layer of aggregates, and then depositing upon this lower layer an upper layer of fines. The

lower layer of aggregates is loose and porous and will notclog the openings of the gratos so that air will readily pass downwardly through both layers of material, after the upper layer of fines has been ignited, and combustion throughout the mass is rapidly propa gated with the result that the sintering operation can be quickly and satisfactorily accomplished in much less time thanis now possible under present practice. One of the main objects of my invention is to provide a method whereby the material to be sintered can be separated into aggregates and fines and disposed in a lower layer of aggregates and an upper layer of fines, this separation of the material and disposition thereof in different layers being accomplished as a continuous operation. In its broader aspects, it is not essential that the method be carried out as a continuous operation, though I prefer to do so as effecting a material saving in time over present methods.

A further object of my invention is to provide simple and elicient means for practicing my method, such -means being capable of movement into and out of operative position, relative to the feed hopper of the machine, in accordance with requirements.

Further objects and advantages of my invention will appear from the detailed description.

In the drawin s:

Figure 1 is a ragmentary side view of the feed end of a sintering machine of the Dwight and Lloyd type, partly broken away, showing separating means in accordance with my invention applied thereto;

Figure 2 isa section taken substantially on line 2 2 of Figure l, looking in the direction of the arrows, the wind box and the shield in front of the feed hopper and screen being omitted for clearness of illustration;

Figure 3 is a semidiagrammatic section through the screen and grate structure and associated parts illustrating the method of my invention and the two layers of material; and

Figure Ltis a semidiagrammatic sectional view through the feed hopper and associated parts illustrating the present practicein depositing the material upon the grate surface.

1 traveling grate structure.

I have illustrated my'invention as applied to a sintering machine of the Dwight` and p Lloyd t pe, by way of example, for which it is particularly well adapted thou h it may be used with other types of mac ines, 4in its broader aspects. The sintering machine comprises a main frame 1 of suitable construction carrying tracks 2 upon which travel pallets 3 of known type. This machine has an endless track, comprising an upper run and a lower run, and is provided with suitable means, such as sprocket wheels, for .elevating the pallets from the lower run to the upper run and ropelling them along the latter. The p lets are provided with grates and the pallets of the train on the upper run of the machine are in contact so as to provide a continuous As the allets travel along the upper run of the trac they first pass beneath a feed hopper by means of which the material to be sintered is delivered to the pallets and is leveled off by a gate memiber in the continued travel of the pallets, after which the pallets pass beneath a suitable device for igniting the material and then, in their continued travel, the pallets passover wind boxes which are connected to suitable suction means for creatin a down-draft through the mass or layer o material on the pallets whereby combustion is propagated downwardly therethrough.

When the pallets reach the delivery or discharge end of the track they pass downwardly about the same and sinter is discharged from the pallets. The construction and operation of machines of this type are well known in the art and need not be illustrated or described here in detail.

A supplemental frame 4 is suitably secured to the main frame 1 and projects upwardly therefrom. This supplemental frame is provided, at its forward end, with uprights 5 which support a feed hopper 6 provided with a downwardly and forwardly inclined rear deflecting wall or plate 7. The material to I.be sintered is delivered to this hopper 7 by means of a swinging spout 8 which swings transversely'of the hopper so as to distribute the material the full width thereof, this spout swinging on an axis extending lengthwise of the machine. Swingin spouts of this type, and means for operating the same, are well known in the art. It is the present practice to dispose the hopper 6 somewhat closer to the pallets 3 than vin Figure 1, the material being discharged from the hopper onto the pallets, after which the pallets pass beneath a gate plate 9 adjustably mounted, as by slot and bolt means 10, upon the uprights 5. y

This plate has a central extension 9a which projects downwardly a suitable distance beyond the top of the pallets and serve to level off and remove the upper portion of the material upon the pallet so as to provide a layer of uniform thickness. The pallet then passes I beneath an ignition device 11, commonly termed an ignition furnace, which serves to ignite the material upon the pallet. Each pallet is providedv wit a grate structure 12 (Figure 3) provided with ksuitable openings for the iiow of air and products of combustion therethrough. After the charge of material has been 1gnited,'the pallet passes over a series of wind boxes 13, in succession, these boxes being connected to suitable means for creating a suction effect therein which serves to draw air downwardly through the material upon grate 12 so as to propagate combustion downwardly through such materia-1. This method of sintering is in accordance with present practice and is well understood in the art.

The method of disposing the material to be sintered upon the grate surface, in accordance with present practice, is illustrated in Figure 4. As previously pointed out,'i t is the present practice to discharge the material from yspout 8 into the feed hopper 6, this material being then discharged from the feed hopper directly onto the moving grates of the pallets. The material is discharged upon the grates in the form of a' pile or ridge which is of approximately conical cross section, as indicated at 14 in Figure 4. In this pile or ridge of material, the coarser particles or aggregates and the relatively minute particles or fines, are mixed indiscriminately and, as the pallets travel beneath the gate plate 9 the pile of material is leveled olf to provide a layer of substantially uniform thickness. In the layer of material thus produced, however, the fines and the aggregates are not segregated but, on the contrary are mixed together indiscriminately and a considerable portion of the fines rest directly upon `the grate surface and act to stop up or clog the openings of the grate with the result-that the air and products of combustion cannot readily be drawn therethrough. In consequence, the rate of combustion of the material is retarded with a resultant curtailment in the production of the machine. I avoid this objection by providing means for separating the fines and the aggregates of the material and then disposing the material in two layers upon the grate, the lower layer consist- 4ing of the aggregates and the upper layer consisting of the lines.

For this purpose I provide a screen struc ture and means for supporting the same for movement into and out of operative relation to the feed hopper 6.

In Figure 1I have shown a screen structure 15 which comprises a suitable frame and casing and a screen 16 disposed within the casing. This screen is operated by an electric motor 17, carried by the screen structure, so as to facilitate passage of material overand through the screen. The screen structure 15 is provided with mounting rollers 18 which travel upon tracks 19l carried by the 'sup 1emental frame 4, the tracks and the rol ers providing convenient'means for moving the screen structure into and out of operative relation to the feed hopper 6. Structure is provided, at each side thereof, with an an le bracket 20 ,suitably secured thereto, t is bracket receiving an eye bolt 21 secured therethrough. The eye of bolt 21 receives the eye of a second eye bolt 22 adapted to be swung into and out of a slot in the outwardly projecting arm of an angle bracket 23 suitably secured to upright 5. A nut 24 screws onto eye bolt 22 and bears against the outwardly projecting arm of bracket 23 for holding the screen structure 15 in operative relation to the ho per.

n angle strip 25, secured to the top of the casing of screen structure 15, is disposed closely adjacent the rear wall of hopper 6 when the screen structure is in the position illustrated. The casing of structure 15 is provided with an opening through its top which, when the screen structure is in operative position, registers with the lower end of hopper 6.

The screen 16 is inclined downwardly and oppositely to the direction of travel of the pallets 3. Wing members 26 proJect rearwardly from the screen structure 15 and support a rod 27 upon which is mounted a curtain structure. This curtain structure comprises a plurality of flat strips 28 mounted at their upper ends upon the rod 27 for free swinging movement about the same. Each of these strips is bent, at its lower portion, to provide an angularly disposed finger 29 which rests loosely upon the upper face of grates 12 of the pallets, as in Figure 3. The material to be sintered is discharged from spout 8 into the hopper 6 from which it passes onto the upper portion of the screen 16. This screen acts to separate the material into fines and aggregates. The fines pass through the screen andthe aggregates are discharged from the lower end thereof. These aggregates are deliected byy the curtain structure onto the upper face of the traveling grate' structure so as to form thereon a. lower loose and porous layer 30. This layer travels with the grate and, in the continued travel thereof, the fines are deposited directly upon the lower layer 30 to form a superposed layer 31 of fines. It is to be noted that these lines are deposited upon the lower layer 30 as separation of the material occurs and, as the pallets pass beneath the gate plate 9, the upper layer 31 is leveled oil' to uniform depth. By depositing the fines upon the lower layer, immediately after separation of the fines from the aggregates, packing of the upper layer..

is prevented and this upper layer 31 of ines is in a loose and fluffy condition so that passage of air therethrough, with resulting combustion after ignition of the upper layer, is greatly facilitated. A further advantage of my invention is that, by my method, the material is separated into fines and aggregatesA and disposed in 'a lower layer of aggregates and an upper la er of'fines, as a continuous operation and uring travel of the grate structure. By thus conditioning the materia-l to be sintered, I render it possible to operate the sintering machine at higher s eed and obtain more complete sintering o the material, than is possible under present practice. This has the great advantage of both increasing the output of the machine and obtalning more complete sintering of the material.

Since the screen 16 is inclined downwardly and contra to the direction of travel of the pallets, and the material, including both fines and aggregates, is delivered onto the upper face of the screen adjacent the upper end thereof, as clearly shown in Figs. 1 and 3 the fines which pass through the screen will increase in size or coarseness toward the lower end of the screen. This means that the layer of fines which is deposited upon the lower layer of aggregates will be progressively increasing fineness from the bottom of the layer of fines to the top thereof, the fines having the greatest degree of fineness bein at the top of the layer. The plate 9 levels o the layer or bed of material so as to assure uniform thickness thereof, and this bed of material is composed of particles which increase in degree of ineness from the bottom of the bed to the top thereof. This graduated bed of material, while in a light and luify and unpacked condition, passes beneath the ignition device 11 where the top of the layer or bed 1s lgnited. By having the bed of uniform thickness and in a light and fluffy and unpacked condition, with the particles of the ed graduated and increasing in degree of fineness from the bottom to the top of the bed, I assure rapid and uniform sintering of the entire bed for the full thickness thereof, thus rendering it possible to perform the sintering operation continuously and at appreciably higher speed than where the material to be sintered is not deposited upon the pallet grate in this light and fluffy and unpacked condition and with the material of the ed graduated and increasing in ineness from the top to the bottom thereof.

In the treatment of certain materials it may be found desirable to deliver such materials4 directly from the hopper 6 onto the pallet grates. To do this, itis only necessary to release the eye bolts 22 and roll the screen structure 15 rearwardl along the tracks 19 into a position complete y withdrawn from beneath the hopper 6. During this movement of the screen structure, the strips 28 of the curtain drag along the grates of the pallet and do not interfer in any way with movement of the /material is not separated into fines and aggregates and disposed upon the pallet grates in separate layers.

The screen structure is of known t e and need not be illustrated nor describe 1n greater detail, it being'suiiicient that a suitable'screen is provided for separatingthe material into lines and aggregates and has associated therewith means for disposing the i aggregates in a lower layer upon the pallet grates, the fines being then disposed in a layer superposed upon such lower layer. There are a number of screen structures which may beadapted for use on sintering machines, and any suitable screen structure may be employed for this purpose.

What I claim is:

l. In a continuousl operating sintering machine; a screen, pa lets travelling'in one directionbeneath the screen, said screen being inclined downwardly and contrato the direction of travel of the pallets, said pallets having grates for reception of material to be sintered and the space beneath the screen and between the underface thereof and the pallet grates being unobstructed, and means for delivering upon' the upper face of the screen and adjacent the upper end thereof material to be sintered and including both iines and aggregates.

2. In a continuously operating sintering machine, a screen, pallets travelling in one direction beneath the screen, said screen being inclined downwardly and contra to the direction of travel of the pallets, said pallets having grates for reception of material to be sintered and the space beneath the screen and between the underface thereof and the pallet grates being unobstructed, means for delivering upon the upper face of the screen and adjacent the upper end thereof material to be -sintered and including both fines and aggregates, and deiiecting means disposed to direct onto the pallet grates material discharged from the lower end of the screen.

3. In a continuously operating sinterin' machine, a main frame, a supplementa frame extending above the main frame, hopper above the supplemental frame, palletstraveling upon the main frame and in one direction beneath the hopper to` receive therefrom material to be sintered, the pallets having grates and the space between the ho per outlet and the pallet grates being uno structed, and a rolling screen structure movable upon the supplemental frame into and out of operative relation to the hopper, said structure comprising a screen disposed between the hopper outlet and the pallet grates and inclined ownwardly and contra to the direction of travel of the pallets, when the screen structure is in operative relation to the hoppen' 4. In a continuously operating sintering machine, a main frame, a sup lemental frame extending above the main rameya hopper above the supplemental frame, allets travcling upon t e main frame an rection beneath the hopper to receive therefrom material to be sintered, the pallets having grates'and the space between the hopper outlet and the pallet grates being unobstructed, a rolling screen structure movable upon the supplemental frame into and out of operative relation to the hopper, said structure comprising a screen dis osed between the hopper outlet and the pa let grates and inclined downwardly and contra to the direction of travel of the pallets, when the screen structure is in operative relation to the hopper, and deflecting means carried by in one dil the screen structure and disposed to ldeflect onto the pallet grates materials discharged from the lower end of the screen.

5. In a continuously operating sinterin machine, a main frame, a supplementa frame extending above the main frame, a hopper above the supplemental frame, allets traveling upon the, main frame an in one direction beneath the hopper to receive therefrom material to be sintered, the pallets having grates and the space between the hopper outlet and the pallet grates being unobstructed, a rolling screen structure movable upon the supplemental frame into and out of operative relation to the hopper, said structure vcomprising a screen dis osed between the hopper outlet and the pa et grates and inclined downwardly and contra to the direction of travel of the pallets, when the screen structure is in operative relation to.

the hopper,- and deflectin means carried by the screen structure an extending downwardly to the pallet grates at an inclination downwardly and in the direction of travel of the pallets, said vdeilecting means being spaced away from and rearwardly of the lower end of the screen and being yieldable in the direction of travel of the pallets.

6. In a continuously operating sintering machine, a hopper, pallets traveling in one direction beneath the hopper to receive therea. from material to be sintered, the pallets having grates and the space between the hopper outlet and the grates being unobstructed, and a screen structure movable into and out of operative relation to the hopper, said structure comprising a screen disposed between the hopper outlet and the pallet grates and inclined downwardly and contra to the direction of travel of the grates, when-the screen structure is in operative relation to the hopper. l 

